Automatic electronic flash units are well known which automatically control the light flash according to light received by the flash unit. Although these flash units greatly simplify flash photography by, for example, eliminating the need to calculate camera aperature according to subject distance, the camera operator must still make certain adjustments to the camera for proper operation. These adjustments generally include shutter speed and aperture settings.
To further simplify flash photography, various "dedicated" electronic flash units have become available which are specifically adapted to cooperate with a given automatic camera. When attached to the camera, such dedicated flash units can perform various functions including setting shutter speed and indicating within the camera viewfinder that the flash unit is ready for operation and, once a flash is completed, indicating that the flash unit light output was sufficient for proper exposure. Moreover, various of the dedicated flash units either generate or respond to special signals which are unique for a particular automaic camera, thus further integrating the dedicated flash unit and the automatic camera.
Despite the availability of dedicated flash units, a considerable number of general purpose automatic electronic flash units have been and continue to be sold. However, the general purpose flash units do not provide the functions of dedicated flash units and thus do not fully utilize the various automatic cameras, making flash photography more difficult.
One adapter which adapts a conventional automatic flash for use with exposure control systems of automatic exposure cameras is disclosed in U.S. patent application Ser. No. 19,297, filed Mar. 12, 1979, now abandoned in favor of continuation application Ser. No. 306,245 filed Sept. 28, 1981 in the same name as the inventor of the present application and assigned to the same assignee of the present application, the disclosure of which is incorporated herein by reference.
Thus, there is a need for an adapter system including a plurality of adapters having substantial common electrical and mechanical components, thus reducing the necessity for individual interface circuits and components. Further, there is a need for an adapter which can adapt a general purpose automatic electronic flash unit to a particular automatic camera which fully utilizes the capabilities of the flash unit and the automatic camera. In this way, existing general purpose flash units can be adapted to fully, yet inexpensively, take advantage of the capabilities of a number of automatic cameras.